Smoke control damper or the like

ABSTRACT

A SMOKE CONTROL DAMPER OR SIMILAR CLOSURE DEVICE INCLUDES AN IMPERFORATE SHEET FOLDED BACK AND FORTH TO FORM BLADE SECTIONS. THE SHEET IS MOUNTED WITHIN A FRAME AND NORMALLY HELD IN AN EXTENDED POSITION, ACROSS THE FRAME, WHEN THE DEVICE IS CLOSED. THE BLADE SECTIONS FORMED BY THE FOLDED SHEET ARE SUBSTANTIALLY PARALLEL WHEN THE SHEET IS IN THE RETRACTED POSITION AND THE DEVICE IS OPEN. WHEN THE SHEET IS EXTENDED, THE BLADE SECTIONS FORM A ZIGZAG PATTERN ACROSS THE FRAME. THE CLOSURE DEVICE IS EFFECTIVE FOR A SMOKE CONTROL DAMPER BECAUSE THERE ARE NO JOINTS OR HINGES BETWEEN ADJACENT BLADES WHICH ARE SUBJECT TO LEAKING AND SUBJECT TO POSSIBLE BINDING AND THUS BEING INOPERATIVE WHEN NEEDED. THE CONSTRUCTION ALSO MINIMIZES THE NUMBER OF PARTS REQUIRED AND REDUCED LABOR COSTS IN FABRICATING THE DEVICE. BY DESIGNING THE SHEET SO THAT IT IS IN A STRESSED CONDITION WHEN CLOSED, THE SHEET CAN BE CAUSED TO AUTOMATICALLY OPEN THE DAMPER WHEN IT IS RELEASED, WITHOUT THE NECESSITY OF EMPLOYING ANY WEIGHTS, SPRINGS, MOTORS, ETC., ALTHOUGH SUCH CAN BE USED, IF DESIRED.

E. H. JOHNsQN ETAL 3,552,901 SMOKE QN'rRoL DAMPER 0R THE LIKE l Filed Dec.. e, 1967 m/VENTORS: EDWARD H. JaHNsaN.

y BY RAvMaNa L. ALLEY.

ATTE/s.

United Statesy Patent O 3,552,901 SMOKE CONTROL DAMPER R THE LIKE Edward H. Johnson, 706 Phillips Ave., Maumee, Ohio 43537, and Raymond L. Alley, 3918 Rushland Ave., Toledo, Ohio 43613 Filed Dec. 6, 1967, Ser. No. 688,390 The portion of the term of the patent subsequent t0 July 28, 1987, has been disclaimed Int. Cl. Ef 15/20 U.S. Cl. 160-1 6 Claims ABSTRACT OF THE DISCLOSURE A smoke control damper or similar closure device includes an imperforate sheet folded back and forth to form blade sections. The sheet is mounted Within a frame and normally held in an extended position, across the frame, when the device is closed. The blade sections formed by the folded sheet are substantially parallel when the sheet is in the retracted position and the device is open. When the sheet is extended, the blade sections form a zigzag pattern across the frame. The closure device is effective for a smoke control damper because there are no joints or hinges between adjacent blades which are subject to leaking and subject to possible binding and thus being inoperative when needed. The construction also minimizes the number of parts required and reduced labor costs in fabricating the device. By designing the sheet so that it is in a stressed condition when closed, the sheet can be caused to automatically open the damper when it is released, without the necessity of employing any weights, springs, motors, etc., although such can -be used, if desired.

This invention relates to a closure device and particularly to a smoke control damper which employs an imperforate sheet of metal to close the damper under normal operating conditions.

The new smoke control device includes a frame and a sheet of metal which is folded in opposite directions at predetermined, spaced intervals to form blade sections corresponding to conventional blades in a damper or shutter, for example. One edge of the folded sheet is attached to a frame member of the frame and the sheet can be held in an extended position across the frame by suitable holding means. The sheet can be in a stressed condition when in its extended position so that it will automatically retract and leave the frame open when the retaining means is released. The sheet also can be retracted with the aid of gravity or a weight attached to the edge opposite the edge attached to the frame, or with the aid of springs, motors, etc.

The smoke control device has relatively few parts so that assembly labor thereof is held to a minimum. Further, the forming of the sheet into the blade sections requires fewer operations and less time than required to form an assemble a plurality of individual blades. The thickness of the metal used in the sheet can also be less than that required for individual blades. In addition, the lack of any hinges between blade sections results in no possibility of hinges binding and being inoperable because of dirt contamination, rust, corrosion, etc. The lack of joints also means that there is no fluid leakage between the blade sections which can otherwise occur, thereby affording maximum protection against wind, rain, etc. Further, the integral blade sections provide maximum strength.

It is, therefore, a principal object of the invention to provide an improved smoke control device having lower labor costs, greater reliability in operation, and minimum possible fluid leakage.

Another object of the invention is to provide a smoke ICC control device having a folded imperforate sheet of metal forming integral blade sections constituting the structure which closes oft` the damper and can lbe opened for smoke release when desired.

A further object of the invention is to provide a smoke control damper having a folded imperforate sheet of metal which, when extended across the frame, is in a stressed condition whereby the sheet will retract and open the damper when released, without the necessity of auxiliary means to accomplish the same.

Many other objects and advantages of the invention will be apparent from the following detailed description of a preferred embodiment thereof, reference being made to the accompanying drawings, in which:

FIG. 1 is a view in -perspective of a smoke control damper embodying the invention and shown in a closed position;

FIG. 2 is a view similar to FIG. l of the damper but in an open position; and

FIG. 3 is an enlarged view in transverse cross section taken along the line 3 3 of FIG. 2.

Referring to the drawings, a smoke control damper embodying the invention is indicated at 10 and includes a frame 12 which is designed to lit into a ceiling or wall. or it can be in a duct rcommunicating with the outdoors. The duct can be designed to establish a draft to facilitate escape of the smoke. The smoke control damper is normally closed and opens in the event of a re to release smoke from the room or other enclosure where the first exists. The frame 12 includes first and second frame members 14 and 16 and side frame members 18 and 20, which are suitably fabricated and joined at their ends by welding or by fastening means. Each of the side frame members has a pair of parallel flanges 22 which extend into the opening formed by the frame 12 and are spaced apart a predetermined distance. The flanges 22 also preferably are located on the bottom frame member 16 and can be on the upper member 14, if desired.

In place of the usual separate, hinged blades, the smoke control damper 10 employs an imperforate, unbroken sheet 24 of metal. The sheet 24 is folded or curved back in opposite directions at spaced, predetermined intervals. as along folds or fold lines 26 (FIG. 3) to form adjacent integral blade sections 28 which conform generally to conventional blades but which are integrally connected at the edges by the folds 26. The folds are parallel to one another and also preferably are parallel to the upper and lower edges of the sheet 24. For larger dampers, two or more of the sheets may be employed, being suitably affixed along edge portions, as by spot welding.

A first edge of the sheet 24 is affixed to the first frame member 14 by suitable fasteners 30, such as rivets or bolts, and a stiffening strip 32. With the sheet 24 in the extended position, as shown in FIG. l, it can be retained by suitable fusible means, shown in the form of a chain 34 and a fusible link 36, with the blade sections 28 then extending across the damper opening in a generally zigzag pattern. The blades preferably are in a stressed condition when extended across the frame so that when the fusible connection parts, the blades will automatically move toward the retracted, unstressed position, as shown in FIG. 3. To assure that the sheet will retract fully when the fusible link 36 is parted, springs or weights and pulleys can be employed in connection with the last one of the blade sections 28. When the smoke control damper is used in a vertical position, the first frame member 14 can be placed at the bottom with the sheet 24 aflixed thereto and a weight ran be aixed to the last one of the blade sections, the uppermost one in this instance, to aid in opening the damper.

The sheet 24 will operate effectively even if made of a number of different metals and in a wide range of thicknesses. The metal and the thickness will depend upon a variety of factors including the cross-sectional shape and the angular positions of the blade sections, the type of environment in which the smoke control damper will be used, e.g. subjected to outdoor weather, dampness, dust, near salt water, etc. The size of the opening of the frame 12 and the width of the blade sections 28 also will influence the choice of metal of which the sheet is made. The length of the sheet can var-y according to the number of blade sections used and their widths. Where fewer, wider blade sections are employed, the thickness of the retracted blade sections will be less than where many, narrower sections are used. With the wider blade sections, however, the frame must be deeper and this is often a disadvantage in many installations, with an overall frame depth of about six inches usually being the maximum desirable.

The material used for the sheet 24 also will depend upon the number of times it is desired that the device be opened and closed without metal fatigue or failure at the folds 26. Even though the device will not be opened or closed to any extent when in use, in many installations, the smoke control damper will be tested by a fire inspector at least once a year. Consequently, it is desirable that the damper be capable of withstanding a number of opening and closing operations without metal fatigue. Where an increased number of opening and closing operations is desired for a given damper, the radii of the folds 26 can be increased, the angle between the blade sections can be decreased, or the thickness of the sheet material can be decreased.

By way of further illustration and not limitation, a specic example of a suitable smoke control damper is set forth. In this instance, the height of the opening of the frame 12 is thirty inches and the width is four feet. The sheet 24 is of 28-gauge galvanized steel and has a length, when flat, approximately three times the height of the opening, or ninety-six inches. The length preferably is from about two to eight times the height, depending on the number and width of the blade sections. The sheet is folded at uniform, four-inch intervals to provide twentyfour 'blade sections, the folds having radii of approximately 1%14 inch. A damper employing a sheet of this type withstood a total of two-hundred-fty complete cycles of opening and closing without any fatigue occuring in the metal at the folds.

When the smoke control damper is in its usual closed position, there are no blade hinges or joints whatsoever to leak and through lwhich wind or rain can pass. At the frame members 16, 18, and 20, the flanges 22 extend inwardly beyond any slight gap existing between the edges of the sheet 24 in the frame members, with any possibilities for leakage at these positions thus being held to a minimum. Further, there are no interlocking joints which might bind, particularly when the blade sections are in the closed, unused position for a number of years. The relatively few parts also reduce labor costs in assembling the damper and even though the area of the sheet 24 would exceed the area of individual blades used in the damper, the metal of which the sheet is made can be thinner than the metal required for individual damper blades.

Numerous modications of the above-described embodiment of the invention will be suggested to those skilled in the art, and in particular, the shape of the folds 2'6 of the sheet 24 can be of numerous designs. It is to be understood that such modications can be made without departing from the scope of the invention, if they are within the spirit of the accompanying claims.

We claim:

1. A smoke control damper comprising a frame including first and second frame members and two side frame members, an imperforate, unbroken sheet having generally parallel rst and SCCQIK! @dges and parallel side edges,

said sheet being folded along substantially equally spaced parallel lines which are also generally parallel to the first and second edges of said sheet and forming blade sections between the fold lines, the adjacent blade sections being structurally integral with one another, the first edge of said sheet being tixed relative to said first frame member with fold lines generally parallel to said r'st and second frame members, sensing means for holding said sheet in an extended position with one of the blade sections near said second frame member and for releasing said sheet if a fire or smoke is sensed, said sheet being internally stressed when in the extended position, whereby the adjacent blade sections of said sheet will retract and move together and cause said sheet to retract rapidly substantially across the opening formed by the frame members to leave the opening open when the sensing means releases said sheet.

2. A smoke control damper according to claim 1 characterized by the length of said sheet between the first and second edges when flat is from two to eight times the distance between said rst and second frame members.

3. A smoke control damper according to claim 1 wherein said side frame members have inwardly-extending parallel flanges spaced apart a distance exceeding the width of said blade sections.

4. A smoke control damper comprising a frame including a plurality of frame members forming an opening, an integral, unbroken, imperforate metal sheet of a size to fully close the opening formed by the frame members when said sheet is in an extended position, one edge of said sheet being aflixed to an adjacent frame member, said sheet being folded back and forth in opposite directions along generally parallel lines to form structurally integral blade sections which are internally stressed when the sheet is in the extended position, sensing means releasably holding said sheet in the extended position with an edge thereof adjacent the frame member opposite said adjacent frame member, whereby the blade sections tend to retract and cause said sheet to move to a retracted position adjacent said adjacent frame member and thereby open the opening, whether the frame is mounted vertically, horizontally, or at any angle therebetween, when said sensing means releases said sheet.

5. A closure device according to claim 4 characterized by the sheet being folded back and forth sharply along fold lines with blade sections formed between the fold lines being substantially planar.

6. A closure device according to claim 4 characterized by the length of said sheet between the iirst and second edges when liat is from two to eight times the distance between two opposite frame members.

References Cited UNITED STATES PATENTS 282,822 8/1883 Willard 98-86 422,665 3/1890 Tryon 98-86 2,940,377 6/1960 Darnell et al. 98-86 2,923,226 2/1960 Wasserman et al. 98-86 451,068 4/1891 Park 160-84 790,632 5/1905 Hall 160-1 2,221,059 11/1940 iPersson 160--84 2,202,358 5/1940 Stone 160--84X 3,273,632 9/1966 McCabe 160-1 FOREIGN PATENTS 543,937 3/1942 Great Britain 16084 365,529 9/1937 Italy 160-84 PETER M. CAUN, Primary Examiner U.S. Cl. X.R. -5, S4 

